This invention relates to determining the position of a mobile platform such as a cart within an environment such as a retail establishment, a warehouse facility, or other large area.
It has been recognized in the past that the ability to determine the position of a mobile platform such as a shopping cart within an area traversed by the platform is useful. As here used, “position” refers both the location, as on an X-Y coordinate grid, and orientation, as with reference to the cardinal points of the compass. Thus position defines both the coordinate grid location and the “pointing” of the cart in a particular direction for next forward movement.
An example of the usefulness of such information is found in prior U.S. Pat. No. 4,882,724 to Vela et al. As there taught, position information is used to provide a basis for shopper information such as the location of products within the establishment relative to the position of the shopping cart. Thus a shopper desiring milk can be directed to the location within a store where milk is on display.
A difficulty which arises with such prior apparatus and methods lies in changes in technology which employ infra red radiation sources and detectors to implement a location determining apparatus and method for shopping carts. In such apparatus and methods, the resolution available with known emitters located above the floor of a space can become challenging. It is this challenge which the present invention overcomes.